JPS5916833B2 - Method for forming slippery thin film - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for forming a slippery thin film.

Thin-film magnetic recording media, ie, vapor-deposited magnetic tape, use a flat plastic film, but the tape has poor lubricity and can cause noise when running.
It is necessary to provide a layer having lubricity on the magnetic surface and the non-magnetic surface.

When providing a slippery layer on the magnetic surface, the thickness of the slippery layer is 100O.
If it is less than A, the electromagnetic conversion characteristics will be adversely affected. Conventionally, when forming a thin film having lubricity, a lubricious substance such as an ester lubricant having a low molecular weight component was mixed into a resin and applied to obtain a lubricious film. However, when the tape is used, severe friction occurs between the metal surface and the tape, which poses a problem in long-term reliability.
The present invention has been made to address these conventional problems, and aims to easily obtain a thin film having slipperiness.

FIG. 1 is a schematic diagram of a device for this purpose. In the figure,
1 is a substrate such as a plastic film to be coated, and 2 is a coating device 0 that coats a mixture of a low-molecular liquid resin that can be solidified by ultraviolet irradiation and slippery particles onto the substrate 1; The structure of the machine is shown. 3 is a hot air drying oven, which is installed so that the coated substrate 1 is heated and a part of the coated mixture is scattered and evaporated with hot air.

The hot air is designed to flow in the same direction as the direction in which the substrate 1 moves. Reference numeral 4 denotes a lamp that generates ultraviolet rays to cure the resin mixture.

Note that 5 is a feeding section for the substrate 1, and 6 is a winding section for the coated substrate 1. FIG. 2 is a sectional view of a resin film in a zero state, which is obtained by applying a mixture of slippery particles to a resin and curing the film by irradiating it with ultraviolet rays without passing through a hot air drying oven.

1 is a substrate, 1 is a resin layer, and 8 and 9 are slippery particles.

In the state shown in this figure, the slippery fine particles tend to form a resin film as shown in 8. Although there are some particles such as the slippery particles in No. 9 that cannot be covered with the resin film, the probability of this happening is low.

"5 FIG. 3 shows the structure of a film created by the process shown in FIG. 1.

1 is a substrate, 10 is a coated resin film, and 11 and 12 are slippery particles.

When the material is passed through a hot air drying oven, the number of slippery particles with a structure partially exposed from the resin layer increases as shown in No. 11. The number of slippery particles covered with resin such as No. 12 is reduced.

FIG. 4 shows the coefficient of friction of the slippery thin films shown in FIGS. 2 and 3 investigated by contact with polished metal.

As can be seen from FIG. 4, the slippery thin film A in FIG. 2 and the slippery thin film B in FIG. 3 have a small coefficient of friction, indicating that they have good lubricity. ■− It is also highly reliable.

As the low-molecular liquid resin used in the present invention, ordinary ultraviolet curable resins can be used, but particularly preferred are those whose main component is a monomer with a boiling point of 300°C or less at 1 atm.
In the case of radical polymerization, monofunctional acrylates such as cyclohexyl methacrylate, t-butylstyrene, and dibutyl maleate, and single or polyfunctional acrylates such as 14-butanediol diacrylate, diethylene glycol diacrylate, and trimethylolpropane triacrylate are used. If the main component is a mixture containing a photosensitizer such as penzone isofububyl ether or benzophenone or other paint additives, it is a di-ion polymerized type, then vinyl cyclohexene dioxide, synchro Pentane edge oxide, dipentene dioxide, 3-
4-epoxycyclohexylmethyl-3-4 epoxycyclohexane carboxylate and other fat-breakable epoxies;
Curing catalysts that produce Lewis acids when di-decomposed by UV irradiation with other epoxies such as allyl glycidyl ether and phenyl glycidyl ether, such as P-nitrobenzenediazonium hexafluorophosphate, 2,4-dichlorobenzenediazonium tetrafluoroboride There are compositions comprising a stabilizer such as acetonitrile propionitrile, etc., and various paint additives added thereto as necessary.

The slippery particles include graphite, graphite, carbon fluoride, graphite fluoride, tungsten dioxide, boron nitride, molybdenum disulfide, and other fine particles with slippery properties. Any powder is fine.

Normally, one of the above resins and a slippery fine powder are used at a mixing ratio of about 0.1% to 50% by weight depending on the purpose, but depending on the purpose, a glaze or other additives may be used. It is also possible to improve the coating properties. A specific embodiment of the present invention will be described below. The clean thin film formed by the present invention shown in FIG. 3 is made of a resin of 3-4 epoxycyclohexylmethyl-3-4 epoxycyclohexane carboxylate and a curing agent of P-nitrobenzenediazonium hexafluorophosphate. ．． Add 5% of graphite fine powder as slippery particles with a weight ratio of 500A to 1000A.
A coating stock solution containing 0% additive dispersed in a ball mill is coated using the coating apparatus of the present invention shown in FIG.

Thickness of film to be applied. The coating was 0.5 μ and the temperature of the drying oven was 12
Flow an air volume of 50 m3/min at 0°C. The length of the drying oven at this time was 5rrL. When dried under such conditions, the applied film thickness will scatter by 0.2 microns, and the slippery particles in that area will be exposed. After this, the surface of the film that has left the drying oven is irradiated with ultraviolet rays,
When the resin is cured, a slippery thin film shown in FIG. 3 is formed. As described above, according to the present invention, a thin film with excellent wave properties can be obtained, and when formed on the film surface of a vapor-deposited magnetic tape, etc., a magnetic tape with good running properties can be obtained. It is.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus used to carry out the method for forming a slippery thin film according to the present invention, FIG. 2 is a sectional view of a slippery thin film not according to the present invention, and FIG. 3 is a cross-sectional view of a slippery thin film according to the present invention. FIG. 4 is a cross-sectional view of the flexible thin film, and is a comparison diagram of the coefficient of friction of the flexible thin films of FIGS. 2 and 3. 1...Substrate, 2...Coating device, 3...
... Hot air drying oven, 4 ... Ultraviolet generating lamp, 10 ... Resin film, 11, 12 ... Slippery fine particles.

Claims (1)

[Claims] 1 Immediately after coating a mixture of a low-molecular liquid resin that can be solidified by ultraviolet irradiation with slippery particles on a substrate, the surface portion of the mixture is passed through a hot air drying oven so that the slippery particles are exposed. A method for forming a slippery thin film, characterized by scattering and evaporating it, and then curing it by irradiating it with ultraviolet rays.